The Windows file name limit has been longer than 255 characters for years, but Windows Explorer was not able to handle names longer than 255 characters. You either had to use a different file manager or cheat with SUBST or DOS commands.
I don't know the actual limit.

On computers running Microsoft Windows*, the PATH environment variable size that you can use is 2047 characters. On computers running Microsoft Windows* 7 and later, the maximum PATH environment variable size that you can use is 4095 characters (but the system restart is required)

What Chuck was talking about is the Path Statement which us used to set the directories that are searched when a program name is entered and is located in the environment variables list. From command prompt type Set and hit enter and you will see it.

What Paul was referring to was the length of a path that cam be used in a programming language/program to access a file. This is the item that would cause problems as in File/Windows Explorer.

In the Windows API (with some exceptions discussed in the following paragraphs), the maximum length for a path is MAX_PATH, which is defined as 260 characters. A local path is structured in the following order: drive letter, colon, backslash, name components separated by backslashes, and a terminating null character. For example, the maximum path on drive D is "D:\some 256-character path string<NUL>" where "<NUL>" represents the invisible terminating null character for the current system codepage. (The characters < > are used here for visual clarity and cannot be part of a valid path string.)

And so, RG / Bruce, I think that, for the purposes of the "ordinary" user (yes, I AM one of those), the limit to the path statement -- that environment variable that used to be part of the autoexec.bat file in the old days -- is, if I am understanding this, 2047 characters today, whereas the path for any specific object or file is (still) 255 characters?